NOTHOFAGUS PUMILIO FORESTS AFFECTED BY TEPHRA DEPOSITION IN NORTHERN PATAGONIA: I - ENVIRONMENTAL TRAITS INFLUENCING SEEDLING GROWTH

MOGUILEVSKY DENISE; FERNÁNDEZ NATALIA; CORNEJO RIVAS PABLO; PUNTIERI JAVIER; FONTENLA SONIA

Journal of Soil Science and Plant Nutrition

Scientific and Biotechnological Bioresource Nucleus BIOREN-UFRO

Lugar: Temuco; Año: 2018

0718-9508

The 2011 Puyehue-Cordón Caulle volcanic eruption left vast areas of Nothofagus pumilio forests covered by high volumes of tephra, which buried the understory. This event offered a unique opportunity to analyse the impact of tephra deposition and the main environmental factors affecting the growth of N. pumilio seedlings. To this end, three study sites were selected, two with a thick tephra layer (50 cm) but with different tree conditions: i) most trees alive or ii) most trees dead, and a third site, iii) without tephra deposition. From each site, five N. pumilio 18-month-old seedlings were collected, morphometrically measured (shoot, epicotyl and root length; shoot, epicotyl and root collar diameter), and environmental factors were also registered (light intensity, soil pH and conductivity, available P, bulk and particle density, and porosity). The main results indicated that three years after eruption the site with tephra deposition and dead trees had the biggest seedlings and the highest values for available P and light intensity. This temporally unique geological event showed that the regeneration potentiality of N. pumilio is high when environmental factors allow direct incident light on a substrate with high mineral content, even when the environment has previously been subjected to a significant degree of disturbance. Given the recurrence of volcanic events in Northern Patagonia, this topic merits further, long-term study.